G1, S, G2, M
Stages of the cell cycle
G1
The stage of the cell cycle where the cell grows and duplicates organelles
S
The stage of the cell cycle where the cell synthesizes DNA
G2
The stage of the cell cycle where the cell continues to grow, and is a critical checkpoint for the DNA
M
The stage of the cell cycle where the nucleus divides, creating two identical cells
Prokaryotic
Do prokaryotic or eukaryotic cells divide faster?
G0
Cells that do not go through mitosis
High
Is a low or high surface area-to-volume ratio better?
Makes transporting molecules more efficient
A high surface area-to-volume ratio does this
Chromosomes
Long continuous threads of DNA
46
How many chromosomes do humans have?
Histones
Proteins DNA wraps around
Chromatids
Tightly coiled chromosomes, shaped like half an X
Sister chromatids
Identical chromatids forming an X
Telomeres
"Caps" formed at the ends of chromatids to keep them together
Centromere
Holds together sister chromatids
Prophase, Metaphase, Anaphase, Telophase, Cytokinesis
Order of mitosis
Prophase
The stage of mitosis in which DNA condenses into tightly coiled chromosomes, the nuclear envelope breaks down, and centrioles move to poles and form spindle fibers
Metaphase
The stage of mitosis in which spindle fibers attach to each chromosome, which each line up along the cell equator (middle)
Anaphase
The stage of mitosis in which chromatids separate to opposite sides of the cell
Telophase
The stage of mitosis in which the nuclear membrane starts to form, chromosomes uncoil, and spindle fibers fall apart
Cytokinesis
The stage of mitosis in which animal and plant cells divide
Cell plate
Plants use this to divide during cytokinesis
Centriole
Plants do not have this organelle used in cell division
Internal & external factors
What regulates cell division?
Physical & chemical factors
External factors that regulate cell division
Growth Factors
Chemical signals sent out by cells that tell surrounding cells to divide
Internal factors
External factors trigger _________ that affect cell cycle
Kinases & Cyclins
The two most important internal factors
Apoptosis
Programmed cell death
Cancer
Uncontrolled cell division
Tumor
Clumps of cells that divide uncontrollably
Benign Tumor
Non-cancerous tumors that remain clustered together and do not spread throughout the body
Malignant Tumor
Cells that break away and spread through the body via the blood stream
Metastasize
The process in which tumors spread throughout the body
DNA Mutations
Cancer cells come from normal cells that have __________
Carcinogens
Substances known to cause cancer
Chemicals, radiation, inheritance, and bad luck
Causes of cancer include
Surgery
The first treatment of cancer
Radiation
Cancer is zapped with this to be treated
Chemotherapy
The last-resort cancer treatment that may kill both cancerous and healthy cells
Homeostasis
Organ systems work together to maintain __________
Cells, tissue, organ, organ system
The order animal structures are divided in
Tissue
Groups of cells working together to perform a function
Organ
Groups of tissues working together to perform a specific function
Organ Systems
Organs that carry out similar functions
Cell Differentiation
The process by which unspecific cells gain specific functions
They read only certain genes
How do cells become specific?
Stem Cells
Cells which can develop into a variety of specialized cell types
Totipotent
Located in a fertilized egg, can become any type of cell
Gene
A segment of the chromosome
Pluripotent
Located in embryonic stem cells, can become almost any type of cell
Multipotent
Located in adult stem cells, can become a closely related cell
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